First, let me say that I know I'm schizophrenic and I apologize for that :). I just received the final results of my last two 5k races and I was faster in the Evo's vs. the zero dropped Nike Free 3.0's, although I placed second in the race in the Evo's and won the race with the Nike Free's. Also, the course I ran in the Evo's was tougher than the course in the Free's as I spent a lot of time analyzing the courses last night and the race in the Free's had more hills but they were smaller while the race in the Evo's had a 1.25 mile gradual uphill climb on the loop toward the finish (I'll take the short hills any day because you get the immediate downhill and mentally it's easier to deal with). In other words, my performance in the Evo's exceeded my performance in the Free's.
I only share this for what it's worth as I've tried several experiments on myself and tried to keep it as close to an apples-to-apples comparison as possible.
I've spent 2 weeks running in the zero dropped Free 3.0's and Run+'s but this morning I returned to the Evo's. I've put about 140 miles on the Free's/Run+'s so my body had time to adjust. I enjoyed running in them and experienced no major pain or injury. I also held my goal times pretty well and tested the shoes on various terrains and elevations. However, as I returned to my Evo's today, among other things, the two words that describes the difference is "CLEAN," and "SHARP," all in favor of the Evo. My run in the Evo's is cleaner and sharper.
It's really interesting because the "energy return," is a comparison between the actual foot vs. the additional cushion. It's really a comparison between the natural functions of the foot/arch and the sole, cushion and mild arch support in the shoe. I've hard coded in my brain most of the elements of good running form and technique but I have to take a more active role in ensuring proper form and technique in the Free's/Run+'s vs. the Evo's. I don't have to think as much in the Evo's as it's easier for the natural body to take over. I can't confirm this but I believe I have a longer stride in the Evo's vs. the Free's/Run's which, on first thought, may be counter-intuitive. I probably actively shorten the stride in more traditional shods while the Evo's, and of course barefoot, provide for a much more natural reaction.
As for the cushioning, yes, it makes a difference. I can't tie it to injury or pain but it feels completely different. With less cushion, I'm a cleaner and sharper runner.
Now, I did do a little barefoot running and that provides an interesting distinction and discussion, at least in my mind, when comparing the Evo to barefoot running. To date, I am faster in the Evo's vs. barefoot and it may be physical or psychological, or a bit of both is probably the case.
I'm having a blast with some of these micro-analysis experiments on myself. Bottom line, is I think Amby Burfoot, Christopher McDougall and that Doctor dude are all correct when they say, "run in the most minimal shoe you can get away with." As with many things in life, when you hit the point where you can add support to the human body but it doesn't need it, you probably should not add it.
Hope some of this is interesting to some folks.